That is VERY helpful--I was going crazy trying to figure it out!
It looks like though you can set a single activity (e.g. Quiz / Discussion Forum) vs. a Course to LTI the grade pass back to an external LMS like Canvas, so that might help some teachers.
Another idea is to use the fantastic SubCourse plugin to push back an entire "unit" of instruction from Moodle as a Course grade to an external LMS--not ideal but at least it gives instructors options....
On another note, I got the LTI integration between Canvas and Moodle working partially, but my dilemma is that in a Moodle a new user account is created with the student's identical email / first name / last name, but NOT mapped to the existing user account that is already in Moodle--a completely new username is created (e.g. "enrol_lti85984fc6add9f757fff3a415eb90a54252f7e280") with a crazy string. Any ideas on how to actually tie the 2 accounts together, or to avoid a new account being created?
That would be the "magic sauce" that would tie the 2 systems together and build synergy between platforms to enable teachers to harness the best of each tool!
Thanks for all your help!